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Pityriasis Rosea, Emergency Medicine

Basics

Description

- Secondary eruption: - Widespread salmon-colored, elliptic, finely scaling papules - Usually appear symmetrically along Langer lines in a "Christmas tree " pattern - Generally follows herald patch by 7 " 14 days - Lesions are concentrated on the trunk and proximal extremities - Pruritus is common

  • A self-limited skin exanthem of unknown origin primarily affecting children and young adults
  • Skin findings often begin with an isolated "herald patch, " an ovoid erythematous raised lesion seen along the trunk and extremities
  • A secondary eruption usually follows, where multiple smaller exanthems appear along the Langer lines of the trunk and proximal extremities in a symmetric "Christmas tree pattern "
  • Nearly 80% of symptoms resolve within 2 mo

Etiology

  • Unknown, although there is weak evidence for a viral etiology such as herpes 6 and 7
  • Many medications have been associated with a pityriasis-like reaction:BarbituratesCaptoprilClonidineGoldIsotretinoinMetronidazoleBismuthHepatitis B vaccineGleevecInterferon
  • Eczema, asthma, and underlying malignancies may be weakly associated

Diagnosis

Signs and Symptoms

Prodromal symptoms and characteristic skin findings are discussed below

History

Prodromal symptoms occur in 60 " 70% of patients:

  • Malaise
  • GI symptoms
  • Respiratory symptoms

Physical Exam

Dermatologic findings

  • Herald patch:Solitary, erythematous, slightly raised papule 2 " 10 cm in diameterSeen in 50 " 90% of cases
  • Secondary eruption:Widespread salmon-colored, elliptic, finely scaling papulesUsually appear symmetrically along Langer lines in a "Christmas tree " patternGenerally follows herald patch by 7 " 14 daysLesions are concentrated on the trunk and proximal extremitiesPruritus is common
  • Lesions concentrated on the face and distal extremities with minimal trunk involvement characterize inverse pityriasis
  • Inverse pityriasis, lesions on the face and distal extremities characterize inverse pityriasis and may be seen more often in pediatric populations
  • Rarely, pediatric presentations may have oral lesions, usually punctate hemorrhage and ulceration

Essential Workup

Exclude other diagnoses, especially when a herald patch is not seen:

  • Secondary syphilis can have similar skin findings. Consider RPR in a patient with STI risk factors
  • KOH prep may diagnose tinea

Diagnosis Tests & Interpretation

Lab

None required:

  • KOH and RPR if other diagnoses are considered

Differential Diagnosis

  • Herald patch:Nummular eczemaTinea corporis
  • Secondary eruption:Secondary syphilisDrug eruptionGuttate psoriasisKaposi sarcomaLichen planusOccult malignancyScabiesSeborrheic dermatitisTinea versicolorDermatomyositisCutaneous lymphomaLupus

Treatment

Initial Stabilization/Therapy

None required

Ed Treatment/Procedures

  • Pityriasis is self-limiting
  • Pruritus may improve after treatment with steroids, antihistamines, and, interestingly, erythromycin

Medication

  • Diphenhydramine: Adult: 25 " 50 mg PO QID (peds: 5 mg/kg/d div. QID)
  • Erythromycin: 400 mg (peds: 10 mg/kg) PO QID
  • Hydrocortisone: 1% cream TID
  • Prednisone: 15 " 40 mg (peds 0.25 " 0.5 mg/kg) daily

First Line

  • Diphenhydramine: Adult: 25 " 50 mg PO QID (peds: 5 mg/kg/d div. QID)
  • Hydrocortisone: 1% cream TID

Second Line

  • Prednisone: 15 " 40 mg (peds 0.25 " 0.5 mg/kg) daily
  • Erythromycin: 400 mg (peds: 10 mg/kg) PO QID

Follow-Up

Disposition

Admission Criteria

Pityriasis rosea is a self-limited disease; admission is not required

Discharge Criteria

Patients with a clear diagnosis of pityriasis rosea may be discharged

Issues for Referral

Severe refractory pruritus may require dermatology follow-up

Follow-Up Recommendations

  • With primary care provider as needed
  • Symptoms usually resolve over 1 " 2 mo

Pearls and Pitfalls

  • Pityriasis is usually limited to the proximal extremities and trunk. Consider alternative diagnoses beyond inverse pityriasis in a patient with mucous membrane or distal extremity involvement.
  • Consider alternative diagnoses in those patients who appear toxic or have atypical presentations.

Additional Reading

  • Browning JC. An update on pityriasis rosea and other similar childhood exanthems. Curr Opin Pediatr. 2009;21:481 " 485.
  • Chuh AA, Dofitas BL, Comisel GG, et al. Interventions for pityriasis rosea. Cochrane Database Syst Rev. 2007;(2):CD005068.
  • Drago F, Broccolo F, Rebora A. Pityriasis rosea: An update with a critical appraisal of its possible herpesviral etiology. J Am Acad Dermatol. 2009;61:303 " 318.
  • Stulberg DL, Wolfrey J. Pityriasis rosea. Am Fam Physician. 2004;69:87 " 91.

Codes

ICD9

696.3 Pityriasis rosea

ICD10

L42 Pityriasis rosea

SNOMED

  • 77252004 Pityriasis rosea (disorder)